A Liquid Crystal Display (LCD) possesses advantages of being ultra thin, power saved and radiation free. It has been widely utilized in, such as LCD TVs, mobile phones, PDAs (personal digital assistance), digital cameras, laptop screens or notebook screens.
The most liquid crystal displays on the market are backlight type liquid crystal displays, which comprises a shell, a liquid crystal panel located in the shell and a backlight module located in the shell.
The common structure of the present liquid crystal panel can comprise a Color Filter (CF) substrate, a Thin Film Transistor Array Substrate (TFT Array Substrate), and a Liquid Crystal Layer located between the two substrates. The working principle is that the light of backlight module is reflected to generate images by applying driving voltages to the two glass substrate for controlling the rotations of the liquid crystal molecules.
The backlight modules can be categorized side-light type backlight module and direct-light type backlight module. In the direct-light type backlight module, the light source, such as Cold Cathode Fluorescent Lamps (CCFL) or Light Emitting Diodes (LED) are located at the rare side of the liquid crystal panel, and the light is distributed by the diffuser plate to form an area light source for the liquid crystal panel. In the side-light type backlight module, the backlight source LED light bars are located at the rare and lateral sides. The light generated by the LED light bars enters the light guide plate (LGP) from the light incident side of the light guide plate. The light injects from the light emitting surface after reflection and diffusion. Then, after transmitting the optical film combination, the area light source is formed for the liquid crystal panel.
With the development of display technology, the liquid crystal display has developed to have high resolution and high color gamut. In the skills of prior arts, the main method of realizing high color gamut is to utilize a blue light emitting chip with the package of red and green phosphor powder and the thickness increase of color filter. As shown in FIG. 1, the LED with the traditional package of Yttrium Aluminum Garnet (YAG) is employed as the backlight source of the liquid crystal display. The NTSC color gamut is only 62% which is far from covering the color gamut range (Pointer's gamut) of all objects' colors of nature. Even for the liquid crystal display with improvements of the backlight source and the color filter to obtain a higher color gamut, the NTSC color gamut only can reach up to 92%, which still cannot cover all objects' colors of nature.
A Field Sequential Color (FSC) liquid crystal display is capable of expanding color gamut in advance. The present Field Sequential Color liquid crystal display rapidly shows red, green blue image information with time division on the liquid crystal display panel. With the human eyes' persistence of vision property, a colorful image can be synthesized. An image frame is divided as several sub color frames and red, green, blue sub images are sequentially displayed. By utilizing the persistence of vision with time division, three primary colors are overlaid and combined and accordingly, the colorful image is shown. However, the color gamut of the present Field Sequential Color liquid crystal display still cannot cover all objects' colors of nature.